char *memmove(dest, src, cnt)
        char *dest, *src;
        unsigned cnt;
        {
        char *p;

                p = dest;
                while (cnt--)
                        *dest++ = *src++;
                return (p);
        }





                 SHR     CX,1     ; convert bytes to words (divide CX by 2)
                 JZ      MovByte  ; jump if number of words is zero
        REP      MOVSW            ; move a word at a time
        MovByte: JNC    Done      ; jump if number of bytes is zero
                 MOVSB            ; move the byte
        Done:



    /*
    **  movtst.c -- program to test the functions moveleft, moveright
    **  and memmove.
    */
    
    char string[]  = { "This is the text in this array" };
    char string2[] = { "This is another, second array" };
    
    main()
    {
    char *retval, *moveleft(), *moveright(), *memmove();
    
            printf("string = -->%s<--\n", string);
            retval = moveright(string, &string[9], 10);
            printf("string = -->%s<--\n", string);
            printf("retval = -->%s<--\n", retval);
            retval = moveleft(&string[2], string, 10);
            printf("string = -->%s<--\n", string);
            printf("retval = -->%s<--\n", retval);
            retval = moveleft(&string[1], &string[22], 8);
            printf("string = -->%s<--\n", string);
            printf("retval = -->%s<--\n", retval);

            printf("\nstring2 = -->%s<--\n", string2);
            retval = memmove(&string2[9], &string2[16], 13);
            printf("string2 = -->%s<--\n", string2);
            printf("retval = -->%s<--\n", retval);
            retval = memmove(&string2[17], &string2[10], 12);
            printf("string2 = -->%s<--\n", string2);
            printf("retval = -->%s<--\n", retval);
    }

Running this program should produce the following output:

    string = -->This is the text in this array<--
    string = -->ne text ine text in this array<--
    retval = -->ne text ine text in this array<--
    string = -->nenenenenenetext in this array<--
    retval = -->nenenenenetext in this array<--
    string = -->nis arrayenetext in this array<--
    retval = -->is arrayenetext in this array<--

    string2 = -->This is another, second array<--
    string2 = -->This is a second arrayd array<--
    retval = --> second arrayd array<--
    string2 = -->This is a second second array<--
    retval = -->second array<--